In the international patent application, WO2006/0247680, from the same applicant, a system comprising a guide tube, a base, a screw and a screwdriver for acting on a dynamic pillar implant is described. The dynamic pillar, which is the object of said invention, comprises two independent pieces constituting the base and the guide tube, or chimney, which are connected to each other by means of an articulation, of which independent pieces the base has a semi-spherical configuration and the chimney has, at the end of the coupling to the base, a complementary configuration, the articulation of which allows the chimney to form a maximum angle of 25° with the base, which is coupled by means of a screw to the longitudinal bore of the implant introduced into the bone, the pieces of which, base and chimney, following casting, form one single metallic piece having the desired angulation, which allows the correct positioning thereof, overcoming any incorrect angular arrangement of the implant in the bone, screwing said structure, at the corrected angulation, directly into the implant.
According to the cited invention, the combination of said pieces, articulated base and chimney, provide a freedom of movement of between 0° and 25° for positioning in relation one another at the desired angle prior to proceeding with the casting. Another object of said invention is the screwdriver (tool for coupling/decoupling by means of a screw of the dynamic pillar of said invention to the implant introduced into the bone), which has a protrusion in the form of a nut head which functions as a tip of the screw for coupling the dynamic pillar to the implant, by means of the complementary housing provided on the head of the screw and which has a substantially spherical configuration defined by a succession of faces constructed by surfaces in the form of interpolation of truncated spherical radii at both ends.
Although the guide tube or chimney has fulfilled the requirement of orientating the screwdriver together with the screw, their characteristics limit the tightening process of said screw at a maximum angle of 25°, producing disadvantages in serving a limited number of applications and solutions to problems, with high probability that the thread will be lost, with low probability of solving aesthetic and functional problems and less flexibility of use.
The screws and the screwdriver of said invention have the following problems, which the present invention solves:                a) Limited angle up to a maximum of 25 degrees;        b) As the spherical tip of the screwdriver has a hexagonal form and the female part of the head of the screw also has the same form, the tightening only occurs by means of the perfect engagement of both;        c) The probability of the screwdriver decoupling from the head of the screw is very high;        d) Reduces the probability of the hexagon of the head of the screw losing its hexagonal form, a very high probability in the currently known systems, which causes the tip of the screwdriver to rotate in its interior, impeding the correct functioning of the assembly during the tightening thereof.        
At the same time, in the prior art there exist different fixing devices for the joining of the two elements, in particular, screws which have heads with different geometries which work with tips of complementary screws for the screwing of the screw to another element by means of a thread. In the prior art, no fixing device with a head at one end and a thread at the opposite end is known which allows the actuation thereof by means of a screwdriver in such a way that between the axis of the tip of the screwdriver and the head of the screw where the tip of the screwdriver is introduced there exists a degree greater than 25° and allows the tightening with sufficient guarantees.